This invention relates to apparatus for making tiles of slabs from castable material particularly concrete.
We have previously proposed such apparatus in relation to making tiles or slabs ranging from roofing tiles to paving slabs, and generally of a type, see our Pat. No. 1302188, where a sequence of platens on an endless conveyor can afford a substantially continuous surface onto which are laid plates and from which dividers are extensible between those plates to sever at least partially a layer of castable (concrete) material charged and compacted onto the plates. Such charging was basically by gravity from a hopper and initial spreading and compaction by associated roller means. Provision was also made for a further charge of finishing material from another hopper and associated spreader roller means with a further compaction stage prior to a drilling stage with positionally adjustable drills necessary for roofing tiles, and a take-off stage for the plates complete with cast and at least partially severed tiles or slabs. That apparatus has proved to be successful over the past fifteen years or so, as have its roofing tile products now well-known by the trade mark HARDROW.
However, that apparatus has certain disadvantages, one of which concerns production of tiles or slabs of different size due to association of the dividers only with leading or trailing edges of the platens, so that platen length has effectively divided one dimension of the tiles or slabs produced, each such divider being raised in turn on a cam track after first compression of the charged and compacted castable material.
The result has been that certain smaller sizes of tiles or slabs have had to be cut down from normal sizes, which involves waste of material.